Method of making a high voltage implanted channel device for vlsi and

Abstract

A process for fabricating a high voltage CMOS transistor having a non-self aligned implanted channel which permits the operation of the device at high voltages. The non-self aligned implanted channel does not require alignment with the gate electrode of the CMOS device, but is accurately implanted early in the fabrication of the device through reliance on direct wafer stepper technology. As a result, the non-self aligned implanted channel does not require a high temperature drive, such that fabrication of the transistor is compatible with VLSI and ULSI processes, and the transistor can be up-integrated onto logic integrated circuits. Accuracy of the placement of the non-self aligned implanted channel provides for a shorter channel length, which enables the device to be highly area efficient while also increasing the current capability of the device. Furthermore, the transistor is characterized by a large field-induced avalanche breakdown voltage, enhanced by a thick gate oxide, a lightly doped drain, a field oxide region between the gate and the drain, and known field plating techniques.